<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<script src="/static/jquery-1.11.3.min.js"></script>
<script>
    $(function () {
       var btnEle = document.getElementById("button");
        console.log(btnEle);

        var $btn = $('#button');
        console.log($btn);

        console.log($(btnEle));
        console.log($btn.get(0));
    });
</script>
<body>
    <button id="button">提交</button>
</body>
</html>